The present invention relates, in general, to a method of producing a thermogenetic semiconductor device and, more particularly, to the use of a two layer epoxy for attaching a leadframe of the thermogenetic semiconductor device to a heatsink.
Since thermogenetic semiconductor die, such as high current transistor devices, create heat while operating, heatsinks are required to dissipate the heat. In attaching the leadframe of a thermogenetic semiconductor device to a heatsink, several characteristics must be considered. Those characteristics are: the actual attachment, heat dissipation, and electrical isolation. Several methods are known in the art for providing such attachment. One of the prior art methods utilizes a laminated layer placed on the heatsink with copper pads placed on the laminated layer. The leadframe is then attached to the copper pads. While the thermal and electrical characteristics of this type of attachment are sufficient, the costs are prohibitive.
A second method of attaching a leadframe to a heatsink is the process of holding the leadframe in a spaced apart relation to the heatsink during plastic encapsulation. The disadvantages to this process are the mechanical difficulties in securing the leadframe and heatsink in a mold press during encapsulation and in the poor thermal properties of the plastic.
Accordingly, it is an object of the present invention to provide an apparatus and method of producing a thermogenetic semiconductor device that overcomes the above deficiencies.
A further object of the present invention is to provide an apparatus and method of producing a thermogenetic semiconductor device which is economical.
Another object of the present invention is to provide an apparatus and method of producing a thermogenetic semiconductor device that provides electrical isolation.
Still another object of the present invention is to provide an apparatus and method of producing a thermogenetic semiconductor device that provides thermal conductivity.
Yet another object of the present invention is to provide an apparatus and method of producing a thermogenetic semiconductor device which allows for pressure to be exerted during bonding.